Knowing Kara she will probably coo and cuddle (or Mehr likely playfully headlock) Conner nicknaming "Baby Cousin" much to his desmise.
But I think they will get along, Conner has a family that can teach him to control his powers and he doens't have to hold back when they're playfully ruff housing
Hmm probably wen they meet each other Kara would get a little jealous but wen she finds out superboy's not fully kriptonian she'll probably tease him about his powers.
Later on in life they'll probably get along and train with each other and Kara would help superboy how to control his powers.
